Generally, electrostatic paint is used for the paint to a workpiece, such as a car body. Electrostatic paint makes electrostatic field between the workpiece side as anode and the paint equipment side as cathode, making the negatively charged atomized paint adsorb to the workpiece by electrostatic force.
As paint equipment performing such electrostatic paint, there is rotary atomizer type electrostatic paint equipment, for example. The paint equipment has a paint gun spraying paint to a workpiece and a robot arm moving the paint gun to the workpiece, rotating the bell cup of the paint gun, making fluid paint which spread on the inside of the bell cup into the state atomized with centrifugal force, charging atomized particles with the electrostatic high voltage impressed by the atomizer etc, and performing electrostatic paint by electrostatic field formed between the grounded workpieces.
This electrostatic paint equipment applies electrostatic high voltage to the metal bell cup and the electrostatic electrode at the tip of the paint gun, charging paint by putting air ions generated from discharge of them on paint, and driving charged paint to stick with the electrostatic force. For this reason, when there is something with a different electrostatic potential from the charged paint except the workpiece, the charged paint adheres to that.
In the paint equipment of rotary atomizer type, it is general to form the spray pattern, called shaping air, with assistance air that controls the form of the spray pattern. The compulsive injection from the shaping air nozzle of this shaping air forms the negative pressure domain of air in the circumference. Moreover, it may be occurred the backlash of the paint atomized by spraying towards the workpiece.
Generally, the external-ornament member of electrostatic painting equipment consists of insulating resin members, and has different electrification potential from that of the paint. Therefore, existence of these negative pressure domains and backlash of the paint, in the circumferences of the painting gun etc., generates electrostatic adhesion of the paint on the surface of resin inevitably to this external ornament member, generating stains.
For example, as shown in FIG. 9, the sprayed paint is flown along with the line of electromagnetic force m formed by bell cup 102a of the painting gun 102, and paints a workpiece 109. However, since the paint particle rebounded on the workpiece 109 and the paint particle floating without adhesion to the workpiece are electrified particles, they adhere to the portions with the low surface potential of electrostatic painting equipment, such as surface of the painting gun 102 which consists of resin members etc., making dirt 102p. 
And since electrostatic attraction becomes so strong that the distance of charged paint and a workpiece is near, the dirt will grow from the tip part of the painting gun 102 near the bell cup 102a. 
Thus, the dirt by adhesion of the atomized paint is a serious problem in the process of painting. That is, if the produced dirt becomes remarkable, the dirt paint will make a spit, adhering to a workpiece, and generating the poor result of painting.
And, although the produced dirt is cleaned in order to prevent poor generating, a painting line stops in this cleaning time. Therefore, when the frequency of cleaning increases, troubles will be largely caused to the painting quantity of production. For the automobile production line which produces the large-sized product under the short baton especially, increase of stopping time in a production line is a very big problem, and it is an important subject constituting the painting equipment which hardly becomes dirty.
Then, conventionally, the electrostatic panel impressed to the same voltage as the painting gun is attached in a painting gun or a robot arm, and the painting gun of the atomized paint and adhesion on a robot arm are reduced by the electrostatic restitution of an electrostatic panel(For example, JPH06-142561, A).
For example, as shown in FIG. 10, in the electrostatic painting equipment 101 with the robot arm 103 supporting the painting gun 102 movably, the electrostatic panel 104 is attached in the basis end of the painting gun 102, making paint mist go to the workpiece side and not to approach the painting gun 102 and the robot arm 103 side by the electrostatic restitution of the electrostatic panel 104.
As mentioned above, it is available to prevent adhesion of the paint mist to the painting gun and the robot arm 103 by causing the repulsion of the paint mist with attaching the electrostatic panel that is impressed the same polar voltage as the painting gun to the electrostatic painting equipment.
However, the electrostatic panel has only a front side in the electrostatic repulsion direction to paint. For example, on occasions when the painting gun 102 moves quickly after injecting the paint as shown in FIG. 11, the paint mist which floats out of the range of the electrostatic restitution of the electrostatic panel 104 will turn to the back side of the electrostatic panel 104, and will adhere to the robot arm 103 etc. Therefore, the dirt cannot be prevented completely. In this case, in order to prevent adhesion of the paint to the robot arm 103 etc., it is necessary to restrict the speed of the robot arm 103 of operation etc., and it affects on the productivity etc.